US3597713A

US3597713A - Current responsive circuit breaker with releasable coupling means, and with circuitry means disposed within a hollow terminal

Info

Publication number: US3597713A
Application number: US788773A
Authority: US
Inventors: James E Mcclain; Argus F Parks
Original assignee: Esco Manufacturing Co
Current assignee: Esco Manufacturing Co
Priority date: 1969-01-03
Filing date: 1969-01-03
Publication date: 1971-08-03
Anticipated expiration: 1988-08-03

Abstract

Disclosed is circuit interrupting apparatus having a pair of remotely spaced conductive terminals for insertion into a line or circuit which is to be protected from overload or fault current. One of the coaxially disposed reciprocatively mounted contact carrier rods adapted to engage and disengage within a substantially evacuated chamber is coupled to spring actuated means and is tripped open by action of a solenoid plunger actuated by an output signal from relay circuitry disposed within one of the remotely spaced conductive terminals. Opening and closing springs respectively retract and advance the movable contact carrier rod, the compression of these springs being effected by latch means which, upon release, retracts the carrier rod from engagement. One of the embodiments discloses a separate trip-free actuating mechanism which cocks the apparatus by advantageous action of a rotatable shaft, linkage mechanism, camming arrangement, and respective collars coupled to the opening and closing springs.

Description

United States Patent [72) Inventors James E. McClain;

Argus F. Paris, both 0 Greenville, Tex. [21] Appl. No. 788,773 [22] Filed Jan. 3, I969 [45] Patented Aug. 3, 1971 [73] Assignee Esco Manufacturing Company Granville, Tex.

[54] CURRENT RESPONSIVE CIRCUIT BREAKER WITH RELEASABLE COUPLING MEANS, AND WITH CIRCUITRY MEANS DISPOSED WITHIN A HOLLOW TERMINAL 10 Claims, 13 Drawing Figs.

[5 6] References Cited UNITED STATES PATENTS 2,658,976 11/1953 Hoye 200/78 X 3,012,118 12/1961 Edmunds 335/6 3,280,282 10/1966 Rodeseike et a1 200/144 (.2) X

3,399,286 8/1968 Kerr, Jr. 200/144 (.2) 3,496,319 2/1970 Norden 200/144 X FOREIGN PATENTS 1,112,745 5/1968 Great Britain ZOO/144.2

Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Atl0rney- Kanz, Glaser and Harwood ABSTRACT: Disclosed is circuit interrupting apparatus having a pair of remotely spaced conductive terminals for insertion into a line or circuit which is to be protected from overload or fault current. One of the coaxially disposed reciprocatively mounted contact carrier rods adapted to engage and disengage within a substantially evacuated chamber is coupled to spring actuated means and is tripped open by action of a solenoid plunger actuated by an output signal from relay circuitry disposed within one of the remotely spaced conductive terminals. Opening and closing springs respectively retract and advance the movable contact carrier rod, the compression of these springs being effected by latch means which, upon release, retracts the carrier rod from engagement. One of the embodiments discloses a separate trip-free actuating mechanism which cocks the apparatus by advantageous action of a rotatable shaft, linkage mechanism, camming arrangement, and respective collars coupled to the opening and closing springs.

PATENTEDAUG 3:911 3.597.713

mvzmons 7 JAMES E. MC CLAIN ARGUS E PARKS ATTORNEYS PATENTEU AUG 3 I911 SHEET U UF 6 l J I O I o 8! N\ m In \n F-ln l m a E N A 8 11 f 5 IE m w a l [I I w i I I O no FIG. 4

ID as FIG. 5

PAIENTEU AUG 3 I971 SHEET 5 OF 6 05 @NN NR 31 mmm illllm .mlllll CURRENT RESPONSIVE CIRCUIT BREAKER WITH RELEASABLE COUPLING MEANS, AND WITH CIRCUITRY MEANS DISPOSED WITHIN A HOLLOW TERMINAL This invention pertains to circuit interrupting apparatus, more particularly to circuit interrupting apparatus of the type to be inserted in an external circuitcarrying large values of current, and even more particularly to circuit interrupting apparatus of the fuse variety having a pair of normally closed coaxially disposed contacts which are opened in response to a spring mechanism activated by relay circuitry responsive to current levels in the external circuitry.

Within the electric power industry, there is a continuing need for newer and more sophisticated devices to protect high power equipment in the event that the currents therein become excessive. Various types of protective devices, such as fuses or circuit breakers have been designed for this purpose, all such devices suffering one or more disadvantages.

It is therefore a primary object of the invention to provide new and improved circuit interrupting apparatus of the type to be inserted into external circuitry whose current is to interrupted.

It is a further object of the invention to provide new and improved circuit interrupting apparatus of the nondestructible type.

It is a still further object of the invention to provide circuit interrupting apparatus of the type responsive to excessive current conditions in the circuit to be interruptedwhich employs an electromechanical relay in its operation.

In accordance with these and other objects, the present in vention is directed to apparatus which includes a pair of coaxially disposed contact carrier rods respectively electrically connected with a pair of remotely spaced conductive terminals adapted for electrical connection in the circuit to be interrupted. One ofthe carrier rods is reciprocatively mounted for respective engagement and disengagement with the other carrier rod, and is mechanically coupled to a spring loaded mechanism which is actuated by an electromechanical relay responsive to sensed current conditions in the external circuit being interrupted. The relay circuitry is desirably located inside one of the cylindrically shaped conductive terminals, and is thus disposed within a uniform electric field. One of the em bodiments includes a separate cocking mechanism for initially compressing a spring, the releasing of this spring from compression advancing the reciprocatively mounted carrier rod into engagement with the other carrier rod.

The various features and advantages of the invention will become more readily understood from the following detailed description taken in conjunction with the attached drawings, where identical numerals refer to similar parts, and wherein:

F IG. 1 is an overall partially broken away perspective view of one embodiment of the apparatus of the invention;

FIG. 2 is a pictorial view ofthe spring actuated mechanism of the embodiment of FIG. 1 illustrating the latch handle in the open position;

FIG. 3 is a sectional view of the apparatus of FIG. 1 taken along the section line 3-3 when the latch handle is in the open position;

FIG. 4 is a top view ofthe apparatus of FIG. 1 with a portion of the housing broken away for clarity of illustration, illustrating the latch handle in the open position;

FIG. 5 is a sectional view similar to the sectionalview of FIG. 3 with the latch handle in the closed position;

FIG. 6 is a top view similar to that of FIG. 4 with the latch handle in the open position;

FIG. 7 is a circuit schematic of one form of relay utilized in the apparatus of the invention;

FIG. 8 is a pictorial view of an alternative embodiment of the spring actuated mechanism of the circuit interrupting apparatus of the invention with a portion of the rear wall broken awav for claritv of illustration:

FIG. 9 is a top view of circuit interrupting apparatus utilizing .the alternative embodiment of the spring actuated mechanism of FIG. 8 when the contacts are disengaged and neither the opening nor the closing springs is compressed;

FIG. 10 is a front view of the alternative embodiment with the contacts and opening and closing springs in the same position illustrated in FIG. 9;

FIG. 11 is a front view similar to that of FIG. 10 with the contacts still disengaged but with the closing spring compressed;

FIG. 12 is a front view similar to that of FIG. 10 with the contacts engaged, and the opening spring compressed; and

FIG. 13 is a pictorial view, partially in section, specifically showing the drive bar, opening and closing springs and related collars.

Referring now to FIG. 1, there is depicted an overall perspective view of one embodiment of circuit interrupter apparatus 10 of the present invention. The apparatus 10 generally includes a conventional vacuum interrupter 20 of the type having coaxially disposed electrically conductive

contact carrier rods

21 and 22 within a substantially evacuated cylindrical housing 23, the

rods

21 and 22 having

contact engaging faces

24 and 25, respectively. The contact carrier rod 22 extends through an end wall 26 of the housing 23, and is fixedly or immovable connected withan enlarged terminal portion 28. Disposed at the opposite end of the apparatus 10 is another enlarged terminal portion 50, the

terminal portions

28 and 50 electrically isolated from one another through support platform 11 and adapted for electrical connection to the circuit whose current is to be interrupted (not shown).

Contact carrier rod 21 extends through opposed end wall 26a of the housing 23, and is coupled to a spring actuating mechanism 30 disposed within the housing 40, the actuating mechanism 30 reciprocating the carrier rod 21 between a closed" position (shown in FIGS. 1, 5 and 6) and an open" position (shown in FIGS. 2-4). When the carrier rod 21 is in the closed" position, the contact faces 24 and 25 are engaged, thus providing a continuous current path through the apparatus 10 between the

terminals

28 and 50. The open" position, on the other end, disengages the contact faces 24 and 25, to interrupt the circuit, all as to be more particularly described.

The spring actuating mechanism 30 includes a latch handle 31 pivotally mounted at the pin 32 and extending through the housing 40, the handle 31 in its forward position when contact faces 24 and 25 are engaged.

The latch handle 31 is connected to a piston member 33 and a cylindrical sleeve 34 by a pin 35 passing transversely therethrough. Piston 33 is adapted for reciprocal movement within a chamber 36 formed by extending cylindrical wall portions of a cylindrical rod 37, the cylindrical rod 37 being rigidly attached, as by way of threaded engagement, with the contact carrier rod 21.

Rod 37 is surrounded at an intermediate location by a bearing 39 through which the rod 37 slides. The cylindrical sleeve 34 is coupled to the rod 37 and the piston 33 by a vertical pin 38 passing through respective slots in the wall portions of the rod 37 and the piston 33.

Located within the chamber 36, and abutting against a forward face of the piston member 33 and a rear internal face of the rod 37 is a spring 50 which is compressed by the forward movement of the piston 33. A second spring 51 of greater diameter surrounds the rod 37 and abuts against wall portions of the sleeve 34 and bearing 39, all as shown in FIGS. 3 and 5.

Securely attached to the movable contact carrier rod 21 is a metallic lug 55 to which the current carrying cable 60 is joined, the cable 60 passing through the coil of a current transformer disposed within the space between the housing 40 and the terminal 50 and electrically connecting the enlarged terminal portion 28 to the terminal portion 50 at the terminal lug 61 when the contact faces 24 and 25 are closed.

Fixed to a wall of the housing 40, and cantilevered over the snrino actiiminc ml thanicm in I: a tawmm m "is". m:

Pivotally mounted to this plate 65 at pin location 66 is a latch finger 67 adapted to cooperate with and engage a roller lug or keeper 68 on the latch handle 31 when the handle 31 is in its forward position (as shown in FIGS. 5 and 6). A leg portion 70 of the latch finger 67 is connected with the movable rod 71 coupled to the solenoid coil 72. A manual trip 82 is also mounted to engage the leg portion 70.

Disposed within, but electrically isolated from the terminal 50, which is desirably cylindrical in shape, is a circuit board coupled to current transformer 85 (connections not shown) and containing various circuit components providing the current relay circuitry 80 schematically shown in FIG. 7. Output wires (not shown) from the circuitry 80 are electrically connected to

terminals

74 and 75 of the solenoid relay 72.

As a specific feature of the present invention, the relay circuitry S0 is wholly disposed within and surrounded by the cylindrically shaped terminal portion 50. As a result, the entire relay circuitry 30 is within a uniform electric field which substantially eliminates any deleterious effects of corona discharge and electrical stresses which would be produced if the circuitry is in a nonuniform electric field.

The entire apparatus 10 is supported by a pair of

spring clips

12 and 13 in which the enlarged

terminal portions

28 and 50 are cradled, respectively, as observed in FIG. 1. The

clips

12 and 13 are affixed to the insulating support platform 11 in any conventional manner, for example by securing extension legs 15 ofthe spring clips to the platform by way of bolts 14.

in accordance with the operation of the apparatus of the invention, the unit 10 may be directly connected by way of

opposed terminal

28 and 50 into an external circuit to be interrupted. The latch handle 31 is then urged forward to the closed position shown in FlGS. 1, 5, and 6, forcing the piston 33 and collar 34 to their forwardmost positions, respectively. This closing of the handle may be accomplished, for example, by inserting an insulating stick, sometimes referred to as a hot stick, through the ring 81 of the handle 31, and forcing or pivoting the handle 31 to its closed position. The latch finger 67 thus engages the roller keeper 68 to keep this handle 31 in this closed position.

The forward motion of the piston 33 compresses the spring 150 within the chamber 36, and thereby transversely thrusts the rod 37 and hence the contact carrier rod 21 forward to engage the contact faces 24 and 25, and close the circuit. As a consequence of the engagement of the contact faces 24 and 25, current in the external circuitry will be uninterrupted, flowing through the terminal 28,

contact carrier rods

22 and 21, cable 60, and terminal 50. The forward motion of the collar 34 also compresses the spring 51 in the manner shown.

The presence of an overload current in the external circuitry will be sensed by the relay circuitry of FIG. 7, as subsequently described, activating the solenoid coil 72 and causing the movable rod 71 to travel in a rearward direction. Since the bar is connected with the leg 70 of the latch finger 67, the rearward travel of the bar 71 causes the latch finger 67 to pivot about its pin point 66 and disengage from the roller keeper 68. This disengagement releases the tension on the

coiled springs

51 and 50, thereby forcing the piston 33, collar 34 (and consequently the rod 37) rearward, to disengage the contact faces 24 and 25.

The disengagement of the

faces

24 and 25 thus opens the circuit and thereby interrupts the current in the external circuit. The circuit may also be manually interrupted by depressing the button 82 abutting the leg portion 70, to thereby pivot the latch finger 67 from the roller lug 68.

Various types of circuit relays 80 may be employed with the apparatus of the invention, a requirement being that it be responsive to excessive current conditions within the external circuit to be interrupted, so as to actuate the mechanism 30 and disengage the

carrier rods

21 and 22 when such excessive current occurs.

FIG. 7 illustrates, however, one form of relay circuitry meeting this requirement. Accordingly, the current flowing through the cable 60 is sensed by current transformer 85, the

output of the transformer being coupled to the solenoid 72 through a voltage

doubler comprising diodes

88 and 89,

capacitors

87 and 90, and resistor 86. Also coupled to the transformer secondary output through rectifying diode 91 is a current level detector comprising unijunction transistor 92 and associated resistors 9396.

Coupled to the output of unijunction transistor 92 through a semiconductor controlled rectifier 97 is a relay composed of coil 98, normally open contact 99, and normally closed contact 100. This relay is connected with a trigger circuit comprising a second unijunction transistor 101, associated

base resistors

102 and 103, and an R-C network consisting of resistor 104 and capacitor 105. The output of the transistor 101 is coupled through another SCR 106 to the solenoid 72.

Capacitors

108 and 109 provide conventional filtering functions and resistor 110 acts as a current limiter.

ln accordance with the operation of the circuit 80, the current within the line 60 is sensed by the transformer 85, a proportional current flowing through the secondary of the transformer. If the magnitude of this current is below a prescribed value, the unijunction transistor 92 is not conducting, the SCR is in its blocking condition, and the

contacts

99 and 100 are in their normally open and closed positions, respectively. Consequently, the unijunction transistor 101 is nonconducting, and the solenoid relay 72 is untripped.

When the line current (and hence the transformer seconda ry current) exceeds the prescribed value, the unijunction transistor 92 conducts, firing the SCR 97, the current thus flowing through relay coil 98 closing the contact 99 and opening the contact 100. This action, in turn, causes transistor 101 to conduct, firing SCR 106, and actuating solenoid 72 and translating bar member 71. As previously described, the translation of bar 72 opens handle 31, thereby to interrupt the line current.

As previously described, the apparatus 10 is inserted into the line portion which it is to protect, and the latch handle 31 is then pivoted forward to engage the contact faces 24 and 25. in the event that there may be a fault in the line, and to prevent closing the contacts into this fault, it is often desirable to utilize a separate switch in series with the apparatus 10, which remains open during the insertion and closing of the apparatus 10, and is then closed after the

contacts

24 and 25 are closed. Any fault current would then open the

contacts

24 and 25, as previously described, and there is no danger of holding the contacts closed and burning out the apparatus. It may be inconvenient or expensive, however, to utilize a separate series switch. Consequently, there is now described, with reference to FIGS. 8-43, another embodiment of the present invention utilizing a modified spring mechanism 30 to provide trip-free action, and eliminate the need for a separate series switch.

Coaxially disposed electrically conductive

contact carrier rods

21 and 22 having the engaging faces 24 and 25 are adapted for reciprocative engagement and disengagement within the substantially evacuated chamber 23, as described in the previous embodiment. Similarly, opposed

terminal portions

28 and 50 are adapted for electrical connection within the line or circuit to be protected. Current carrying cable lug 55 is secured, as before, to movable rod 21 and provides the electrical connector for the cable 60 (not shown) coupled to the terminal 50; and relay circuitry is disposed, as before, within one of the terminals 50.

In rigid engagement, as by threading, with the carrier rod 21 is an elongated cylindrical drive bar 200 reciprocatively mounted within the housing 40. The forward and rearward motion of the drive bar 200 thus respectively closes and opens the

contacts

24 and 25 by advancing and retracting the laterally movable rod 21.

As subsequently described, the forward and rearward (reciprocative) motion of the drive bar 200 is effected by the action and reaction ofa pair of

springs

201 and 202 which are disposed around the bar 200. Accordingly, one end of opening spring 201 abuts against an inside face of the shoulder or projection 204 of the housing 40 (FIGS. 11-13); the other end abuts against an inside face 205 of the collar 206 which is rigidly connected by pin 207 to the drive bar 200. Similarly, closing spring 202 has one end abutted against the inside face of another shoulder or projection 208 of the housing 40; the other end of the spring 202 abutting against an inside face 210 of the collar 212, the collar bar 200.

Pivotally mounted at the pin 213 to the collar 212, as best seen in FIG; 13, is a linkage mechanism 215 having a pair of linking arms 216. Shoulder portions 218 of each of the arms 2.16 are adapted to engage a pair of roller keepers 217 extending from the forward collar 206.

Apparatus for cocking the spring actuated mechanism 30' of the present embodiment includes latch handle means 220, cocking

linkage

221a and 221b, cocking shaft 222, and

flanged hubs

223a and 223b.

Latch means 220 has its pair of legs 224 pivotally mounted at the pin 225, and is coupled to the linkage mechanism 215 and the collar 212 by the pin 213. The means 220 includes a roller lug or keeper 256 which engages a latch finger 226, as subsequently described in more detail.

A pair of linkage arms 221a pivotally joined to the latch means legs 224 are also respectively pivotally joined to one end of linkage arms 221b at pin locations 227. Disposed at the opposite ends of linkage arms 22112 are hubs 228 through which the cylindrical cocking shaft 222 passes for rotation therein. Extending from one of the linkage arms 2210 is a protrusion 229.

Also disposed about opposite ends of shaft 222 for rotation therewith are

flanged hubs

223a and 223b, each of these flanged hubs having a projection or boss 230 which engages the linkage arms 221b when the shaft 222 and hubs 223a and 22317 are rotated through the requisite arc.

A trip arm 231 having a cam extension 250 is pivotally mounted at pin location 232, one end of the arm 231 connected to a spring 233, the free end adapted to be engaged by a latch finger 234 pivotally mounted to the frame 40 at the pin 235. The latch finger 234 is connected to the plunger 71 ofthe solenoid 72, solenoid 72 being coupled to the same relay circuitry 80 previously described.

Pivotally mounted to the top of the shoulder extension 208 at the pin location 240 is the latch finger 226 adapted to cooperate with and engage roller lug or keeper 256 on the latch handle means 220 when it is in its rearwardmost position. An extension leg 241 of the latch finger 226 is adapted to cooperate with and engage an extension portion 242 of a slide bar 243 (FIG. 8). At the other end of the slide bar 243 a boss 244 is disposed so as to cooperate with and be engaged by a lip 245 of the flanged hub 223b, as well as act as a cam follower to the cam surface 246 of the hub 2231). Another extension 247 of the slide bar 243 is adapted to engage a protrusion 252 from one of the legs 216 of the linkage 215 (FIG. 8). 7

There is now described with respect to FIGS. 8-13 the operation of the embodimentjust described. Accordingly, the circuit interrupting apparatus is connected by way of

terminals

28 and 50 into the external line or circuit to be protected with the contact faces 24 and 25 disengaged, the drive bar 200 and rod 21 in their rearwardmost position, and the latch handle 220 rotated to its forwardmost position, as pictured in F165. 9, 10 and 13. The bottom surfaces 270 of each of the arms 216 rest on top of the roller keepers 217. Opening and closing springs 201 and 202 are in their relaxed or uncompressed condition.

A removable lever handle 260 is then fitted over an end portion 251 of the shaft 222, and rotated in a clockwise direction until the projections 230 on the flanged hubs 223a and 2231; respectively engage the pair oflinkagearms 221b,'forcing the

linkage arms

221a and 221b rearward. This movement correspondingly pivots the latch handle 220 to its rearwardmost position until the latch finger 226 engages roller keeper 256 (P16. 11). This pivoting ofthe latch handle 220 in turn forces the rear nnllar 7.12 rnarwarrl r'nmnrpccinn flan (nl'irtfl 001 qnrl 212 slidably mounted on the drive the keepers 217.

.leg 241 enabling the linkage mechanism 215 to drop or pivot downward, the surface portions 280 now resting on the roller keepers 217, and the shoulder portions 218 disposed directly behind the roller keepers 217. While a narrow space is illustrated in FIG. 11 between the roller keepers 217 and the shoulder portions 218, these portions 218 may directly abut The engagement of the finger 226 with the keeper 256 thus holds the spring 202 compressed and the collar 212 in its rearwardmost position.

As a consequence of the rearward travel of the linking arms 221a, and due to the resulting engagement of the protrusion 229 during this rearward travel, the trip arm 231 is pivoted about the pin 232 until the free end of the trip arm 231 is engaged by the latch finger 234. During all this movement, the drive bar 200 and carrier rod 21 remain in their rearwardmost positions, the

contacts

24 and 25 thus remaining open.

The lever handle 250 (and shaft 222) is next rotated in a counterclockwise direction until the lip 245 engages boss 244, as viewed in FIG. 8. Further rotation thus forces the slide bar 243 forward, impressing the extension portion 242 against the to thereby pivot the latch finger 226 into disengagement from the roller keeper 256. This disengagement thereby releases the tension on the compressed spring 202, the resulting driving force of the released spring thrusting the collar 212 and linkage mechanism 215 forward. This forward motion impacts the shoulder portions 218 against extensions 217 of the front collar 206, thus forcing this collar 206 forward, compressing the spring 201, and advancing the drive bar 200 and rod 21 until the contact faces 24 and 25 are engaged, all as illustrated in FIG. 12. The external circuit or line being protected is now closed.

The presence of any overload current in this external circuit will be sensed by the relay circuitry of FIG. 7 in the manner previously described, the resulting output translating the plunger 71 of the solenoid 72 so as to pivot the latch finger 234 out of engagement with the trip bar 231. The stored force of the spring 233 then pivots the released trip bar 231 about pin location 232, forcing the cam extension 250 against the bottom surface 270 of the leg 216, thereby pivoting linkage means 215 counterclockwise until shoulder portions 218 disengage frorn rollers 217. This disengagement, in turn, releases the collar 206 and the opening spring 201 from compression, the collar 206 (and drive rod 200) thereby being thrust rearward, disengaging contact face 24 from contact face 25, and interrupting the circuit.

This disengaging may also be effected manually, if desired, by rotating the shaft 222 (and flanged hub 223b) in a clockwise direction, the cam surface 246 thereby forcing the boss 230 (and slide 243) rearward to shove the extension 247 against the protrusion 252, also resulting in the pivotal disengagement ofthe mechanism 215 from the rollers 217.

Various modifications of the disclosed embodiments as well as additional embodiments may become apparent to those skilled in the art after reviewing the foregoing description without departing from the spirit and scope of the invention as defined by the following claims.

We claim:

1. In a circuit of the type having apparatus included therewith for interrupting the flow of current in said circuit, said apparatus comprising:

a. a pair of remotely spaced terminals for electrical connection with said circuit;

b. a substantially evacuated chamber;

c. a pair of coaxially disposed carrier rods respectively electrically connected with said remotely spaced terminals, each of said carrier rods having contact faces at ends thereof disposed within said substantially evacuated chamber;

d. spring loaded means coupled to one of said contact carrier rods for advancing and retracting said one carrier rod into engagement and disengagement, respectively, with e. relay circuitry responsive to said current flow increasing above a predetermined value for actuating said spring loaded means, thereby to retract said one carrier rod from said engagement, whereby the said current flow is interrupted, said relay circuitry being disposed within a uniform electric field established by-said current fiow.

2. The apparatus as described in claim 1 wherein one of said remotely spaced terminals is cylindrical in shape, and said relay circuitry is disposed solely within said one cylindrical terminal.

3. The apparatus as described in claim 4 wherein said spring loaded means comprises a first spring for advancing said one carrier rod into said engagement, a second spring for retracting said one carrier rod from said engagement, a pivotally mounted latch handle for compressing said first and second springs when in a closed position, a latch finger for retaining said latch handle in said closed position, and trip means coupled to said latch finger for releasing said latch handle from said closed position, said relay circuitry actuating said trip means.

4. The apparatus as described in claim 3 wherein said one carrier rod has an extension thereof having wall portions defining a cavity, a piston member and said first spring within said cavity, a sleeve member and said second spring surround ing said wall portions, said pivotally mounted latch handle coupled to said sleeve member and said piston member, a solenoid, when actuated, adapted to have means thereof engaging a leg portion of said latch finger, saidrelay circuitry actuating said solenoid, thereby to disengage said latch finger from said latch handle.

5. Circuit interrupting apparatus, comprising:

a. a pair ofremotely spaced terminals for electrical connection with an external circuit which current is to be interrupted;

b. a pair of coaxially disposed contact faces respectively electrically connected with said remotely spaced terminals;

c. a reciprocatively mounted drive rod coupled to one of said contact faces for advancing and retracting said one contact face into respective engagement and disengagement with the other contact face;

d. first and second springs e. first and second collars in respective engagement with said first and second springs, said first collar slidably mounted on said drive rod, said second collar rigidly attached to said drive rod;

. first means pivotally mounted to said first collar for coupling said first collar to said second collar;

g. second means coupled to said first collar for sliding said first collar along saiddrive rod, thereby to compress said first spring, and to cause said first means to pivot into coupling engagement with said second collar; said drive rod and said second collar, whereby said contact faces engage one another, and said second spring is compressed;

j. second release means coupled to said first means for pivoting, when actuated, said first means out of coupling engagement with said second collar, thereby to release said second spring from compression and retract said drive rod, whereby said contact faces are disengaged; and

k. relay circuitry responsive to overcurrent flow in said external circuit coupled to said second release means for actuating said second release means.

6. The apparatus as described in claim 5 wherein said second means comprises:

i. a pivotally mounted latch handle coupled directly to said first collar;

ii. a rotatably mounted shaft coupled to said pivotally mounted latch handle, said shaft having at lease one flanged hub disposed on one end thereof for rotation therewith, said hub adapted to engage said first release means; and

iii. means for rotating said shaft in one direction, thereby to pivot said latch handle so as to slide said first collar and and thereafter in an opposite compress said first spring, direction, thereby to engage said hub with said first release means, whereby said first release means is actuated.

7. The apparatus as described in claim 6 wherein said second release means includes a solenoid which input is coupled to the output of said relay circuitry, and said flanged hub includes means coupled to said second release means for actuating said second release means when said shaft is rotated.

8. interrupting apparatus of the type to be connected with an external circuit, which current is to be interrupted, said apparatus comprising:

a. a pair of remotely spaced conductive terminals for electrical coupling with said external circuit,

b. a pair of collinearly disposed contact carrier rods respectively electrically connected with said remotely spaced terminals, at least one of said rods being reciprocatively mounted for respective advancement and retraction of said contacts toward and away from engagement with one another,

c. first means releasably operationally coupled to said reciprocatively mounted carrier rod for urging said reciprocatively mounted carrier rod forward during said coupling, thereby to advance said contacts toward said engagement, the release of said first means from said operational coupling preventing said advancement,

d. second means coupled to said reciprocatively mounted carrier rod for urging said reciprocatively mounted carrier rod rearward, thereby to retract said contacts away from said engagement, and

e. means responsive to current flow through said external circuit exceeding a predetermined level for releasing said first means from said operational coupling with said reciprocatively mounted carrier rod, whereby when said first means is released, the contacts are prevented from advancing further toward engagement and the second means retracts any prior advancement of the said contacts.

9. The apparatus as described in claim 8 wherein said first means comprises a closing spring having energy stored therein, said second means comprises an opening spring having energy stored therein, the forward movement of said reciprocatively mounted carrier rod storing energy within said opening spring, and further including third means for compressing said closing spring to store energy therein, fourth means for temporarily holding said closing spring in said compression, and fifth means for releasing said closing spring from compression.

10. The apparatus as described in claim 9 wherein said contacts are disposed on respective one ends of said carrier rods within a substantially evacuated chamber,.and wherein one of the said rods is fixedly connected with one of said conductive terminals.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 597 713 Dated Aug 3 1971 Inventor(s) James E McClain et a1 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 25, "immovable" should read immovably line 75 is illegible and should read spring actuating mechanism 30 is a platform or plate 6 Column 3 line 54 after "bar" insert 7l Column 5, line 75 is illegible and should read the rear collar 212 rearward compressing the spring 202 and Column 6, line 75 is illegible and should read said other carrier rod; and Column 7, line 11, the claim reference numeral "4" should read l line 52, cancel "said drive"; lines 53 and 54 cancel "rod and said second collar, whereby said contact faces engage one another, and said second spring is compressed;" and insert:

(h) latch means coupled to said second means for holding said first spring in compression; (i) first release means for disengaging, when actuated,

said latch means from said second means, thereby to release said first spring from compression and advance said drive rod and said second collar, whereby said contact faces engage one another, and said second spring is compressed;

Signed and sealed this 2nd day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 3RM PC4950 (10-591 USCOMM-DC 60376-P69 D U 5 GOVERNMENT PRINTING QFFICE 1969 0*355'334

Claims

1. In a circuit of the type having apparatus included therewith for interrupting the flow of current in said circuit, said apparatus comprising: a. a pair of remotely spaced terminals for electrical connection with said circuit; b. a substantially evacuated chamber; c. a pair of coaxially disposed carrier rods respectively electrically connected with said remotely spaced terminals, each of said carrier rods having contact faces at ends thereof disposed within said substantially evacuated chamber; d. spring loaded means coupled to one of said contact carrier rods for advancing and retracting said one carrier rod into engagement and disengagement, respectively, with said other carrier rod; and e. relay circuitry responsive to said current flow increasing above a predetermined value for actuating said spring loaded means, thereby to retract said one carrier rod from said engagement, whereby the said current flow is interrupted, said relay circuitry being disposed within a uniform electric field established by said current flow.

4. The apparatus as described in claim 3 wherein said one carrier rod has an extension thereof having wall portions defining a cavity, a piston member and said first spring within said cavity, a sleeve member and said second spring surrouNding said wall portions, said pivotally mounted latch handle coupled to said sleeve member and said piston member, a solenoid, when actuated, adapted to have means thereof engaging a leg portion of said latch finger, said relay circuitry actuating said solenoid, thereby to disengage said latch finger from said latch handle.

5. Circuit interrupting apparatus, comprising: a. a pair of remotely spaced terminals for electrical connection with an external circuit which current is to be interrupted; b. a pair of coaxially disposed contact faces respectively electrically connected with said remotely spaced terminals; c. a reciprocatively mounted drive rod coupled to one of said contact faces for advancing and retracting said one contact face into respective engagement and disengagement with the other contact face; d. first and second springs e. first and second collars in respective engagement with said first and second springs, said first collar slidably mounted on said drive rod, said second collar rigidly attached to said drive rod; f. first means pivotally mounted to said first collar for coupling said first collar to said second collar; g. second means coupled to said first collar for sliding said first collar along said drive rod, thereby to compress said first spring, and to cause said first means to pivot into coupling engagement with said second collar; said drive rod and said second collar, whereby said contact faces engage one another, and said second spring is compressed; j. second release means coupled to said first means for pivoting, when actuated, said first means out of coupling engagement with said second collar, thereby to release said second spring from compression and retract said drive rod, whereby said contact faces are disengaged; and k. relay circuitry responsive to overcurrent flow in said external circuit coupled to said second release means for actuating said second release means.

6. The apparatus as described in claim 5 wherein said second means comprises: i. a pivotally mounted latch handle coupled directly to said first collar; ii. a rotatably mounted shaft coupled to said pivotally mounted latch handle, said shaft having at lease one flanged hub disposed on one end thereof for rotation therewith, said hub adapted to engage said first release means; and iii. means for rotating said shaft in one direction, thereby to pivot said latch handle so as to slide said first collar and compress said first spring, and thereafter in an opposite direction, thereby to engage said hub with said first release means, whereby said first release means is actuated.

8. Interrupting apparatus of the type to be connected with an external circuit, which current is to be interrupted, said apparatus comprising: a. a pair of remotely spaced conductive terminals for electrical coupling with said external circuit, b. a pair of collinearly disposed contact carrier rods respectively electrically connected with said remotely spaced terminals, at least one of said rods being reciprocatively mounted for respective advancement and retraction of said contacts toward and away from engagement with one another, c. first means releasably operationally coupled to said reciprocatively mounted carrier rod for urging said reciprocatively mounted carrier rod forward during said coupling, thereby to advance said contacts toward said engagement, the release of said first means from said operational coupling preventing said advancement, d. second means coupled to said reciprocatively mounted carrier rod for urging said reciprocatively mounted carrier rod rearward, thereby to retract said contacts away from said engAgement, and e. means responsive to current flow through said external circuit exceeding a predetermined level for releasing said first means from said operational coupling with said reciprocatively mounted carrier rod, whereby when said first means is released, the contacts are prevented from advancing further toward engagement and the second means retracts any prior advancement of the said contacts.

10. The apparatus as described in claim 9 wherein said contacts are disposed on respective one ends of said carrier rods within a substantially evacuated chamber, and wherein one of the said rods is fixedly connected with one of said conductive terminals.